March 10 – Ice, Ice, Baby

Today’s factismal: As a glacier melts, it makes sounds that are louder than a chainsaw.

Though landlubbers may think of the ocean as being silent, seafarers know the truth. As early skin-divers and scuba explorers discovered, the ocean is full of sounds ranging from the continual grinding of parrot fish jaws as they eat the coral reefs around them to the throbbing booms made by drum fish as they beat their swim bladder with their abdominal muscles. And perhaps the best known example of ocean sounds are the various calls of the whales, from the friendly bottlenose dolphin’s whistles and clicks as it searches for food to the blue whale’s explosive shouts that cover half the ocean.

This parrot fish is actually pretty noisy (My camera)

This parrot fish is actually pretty noisy
(My camera)

It isn’t only critters that make noise in the water. Volcanic eruptions from the mid-Atlantic ridge and mid-Pacific seamounts hiss and sputter as the hot rock is suddenly quenched by the ice-cold water. Landslides along the continental shelves rumble threateningly as they dump tons of sediment and nutrients into the benthic ocean. Earthquakes fill the water column with a rolling thunder. And, surprisingly, even the glaciers add their soupçon of susurrus to the mix. You see, glaciers are formed when snow piles up faster than it can melt. As the snow piles higher and higher, it squeezes the individual snowflakes into a solid mass of ice. During the process, most of the air is squeezed out, but small bubbles can get trapped.

This is where the glacier meets the sea (My camera)

This is where the glacier meets the sea
(My camera)

If the glacier is on a slope that heads down toward the ocean, it will slide downhill and create what is known as a tidewater glacier. The weight of the ice mass up high in the mountains pushes the glacier oh so slowly out into the water, where it breaks off in bits. But, because the water is slightly warmer than the glacier, the ice at the bottom of the glacier melts. As it melts, it releases those air bubbles that were trapped so long ago. And those suddenly freed bubbles spring into a near-perfect sphere with a sudden “gloing!” of freedom. When enough of those bubbles pop open, it creates a 120 dB ruckus that is louder than a chainsaw!

A glacier calving; this isn't the noisy part! (My camera)

A glacier calving; this isn’t the noisy part!
(My camera)

Now the interesting thing about that sound is that it isn’t all bad. Seals and sea lions like to dive near glaciers, looking for fish to eat. And orcas like to dive near the seals and sea lions, looking for something to eat. But where seals use their eyes and whiskers to search for food, orcas use sound; like other whales, they send out a sonar beam that gets reflected off of things nearby helping the orca to locate a likely snack. But the constant noise of the glaciers makes it hard for the orcas to hear the reflected sound of their sonar; like someone trying to whisper in a rock concert, it just doesn’t work very well.

An orca's favorite snack (My camera)

An orca’s favorite snack
(My camera)

If you’d like to learn more about how orcas use sound to track their prey (and maybe even use the orcas’ own sounds to track them!), swim over to Orcasound.net:
http://www.orcasound.net/

March 7 – Seven Impossible Things

Ah, Saturdays! Is any day better? You get to sleep late, you get to watch cartoons, and (best of all) you get another Secret Science Society adventure! Today, Mary and Peter discover that there are somethings that man is not meant to know…

Most days, Peter and Mary got along well together. They both liked the same things, and they both wanted to be scientists. But every once in a while, they would fight. And, as is often the case with friends, when they did fight it was usually about something stupid. Today was no exception.

“There is so!” Mary shouted.

“No there isn’t!” Peter insisted. “There isn’t anything that is impossible!”

Attracted by the noise, Peter’s mother came into the den. “What is all the fuss about?” she asked.

“Tell Mary that there isn’t anything that’s impossible!” Peter demanded. “We might not be smart enough to figure it out, but there is always a way to do anything.”

“It is true that we’ve learned how to do a lot of things that people used to think were impossible,” Peter’s mother said. “We can fly faster than the speed of sound; there’s even been a car that drove that fast. We can orbit the Earth, and cure many diseases, and feed billions where millions used to starve.”

“See!” Peter interjected.

“Ah, but maybe there are some things that are impossible,” Peter’s mother continued. “Let me give you an experiment to do on impossibility.”

At that, both Peter and Mary perked up. Doing experiments was one of their favorite activities.

“Let me borrow the chalk and let’s go out to the sidewalk.” Picking up the chalk, Peter’s mother led them all to the sidewalk. “OK, here is the problem. Let’s pretend that the sidewalk is a river. In it are two islands, here and here.” Quickly, she sketched in two large ovals in the middle of the sidewalk. “Now on the big island, there are five bridges. Two go to the east side of the river,” she paused to sketch in two bridges leading to the lawn closest to them. “Two more go to the west side of the river,” she again paused to sketch in two more bridges leading to the lawn on the other side of the sidewalk. “And one goes to the little island. But it also has a bridge going to the east side of the river and another going to the west side.” She finished drawing the last three bridges and stood up. “Now here’s the challenge: Can you walk over all seven bridges without having to walk over any bridge twice? Is it possible to walk over all the bridges just once?”

The bridges

The bridges

“No way!” Mary said. “That’s impossible!”

“There’s no such thing,” Peter insisted. We just haven’t figured it out yet!”

“Well, I’ll be inside working on my exoplanet research,” Peter’s mother said. “Come and get me when you figure it out.”

As she walked into the house, Peter and Mary turned to the sidewalk and started trying different paths.

What do you think will happen? Do the experiment!

 

 

 

 

After about an hour, the two crept back into the house and found Peter’s mother staring intently over light curve data from the latest astronomy satellite.

“I give up,” Peter said. “How do you do it?”

“That’s easy,” his mother replied. “You don’t. This is a famous mathematics problem known as the Königsberg Bridges Problem. You see, in Germany, in a little town called Königsberg, they actually have seven bridges laid out just the way we drew them on the sidewalk. And people used to spend their Sunday afternoons trying to walk over all of the bridges exactly once.”

“This must have been before television,” Mary said.

“Yes, there wasn’t much else to do on Sundays back then. Now, to solve the problem a smart guy by the name of Euler decided that it was much too tiring to walk. Instead, he drew the problem as a bunch of dots connected by lines. There was one dot for the east side, one for the west side and one for each island. And each bridge was a line connecting the dots to each other.”

Peter’s mother turned over a scrap piece of paper and sketched out the diagram.

Euler's solution

Euler’s solution

“Now, Euler simply counted the number of lines leading to each dot. The only way that you can cross all of the bridges only once is if there are no dots with an odd number of lines, or if exactly two dots have an odd number of lines.”

“But we have four dots with an odd number of lines, so that’s impossible.” Peter said.

“Right. The neat thing about this is that highway engineers still use it to help design new interchanges. And computer engineers use it to design computer circuits.”

“So even though it is impossible, it is useful!” Mary said.

“That’s right. And if you’d like a real challenge, spend some time figuring out how many bridges you’d have to add to make the walk possible, and where you’d put them.”

With that, the two headed back out to the sidewalk to build some bridges.

March 6 – We Did It!

Today’s factismal: For the first time in human history, we have launched a spacecraft that has orbited two bodies other than the Earth!

Today marks a very special day in spaceflight history. That’s because, as of today, spaceflight no longer means orbiting just one new planet. Up until today, every probe that we sent out would orbit just one planet (other than the Earth). If the probe was sent to the Moon, it could orbit the Moon but it couldn’t orbit the Moon and then head over to Mars. If it was sent to Mars, it could orbit Mars but it couldn’t orbit Mars and then head over to Jupiter. And so on. If we wanted to send a probe to more than one planet (as we did with the Voyager probes) then we had to send it on fly-by trajectories that let us get close to each planet but not spend much time there. Naturally, that limited both the quantity and the quality of the science that could be done and the pictures that could be taken. (How many pictures could you take of Disneyworld if you were driving past at 600 mph?) But as of today, that is no longer true. Today the DAWN probe has gone into orbit around Ceres after previously orbiting Vesta.

The path that DAWN has taken (Image courtesy NASA/JPL)

DAWN’s long, strange trip
(Image courtesy NASA/JPL)

DAWN was able to do this thanks to her ion engine. This rocket motor is so weak that it couldn’t lift the probe a millimeter off the ground on Earth. But in space, even a weak thrust adds up over time, which allowed DAWN to slowly move away from Earth and into the asteroid belt where Vesta and Ceres live. These two rocks are the largest of the asteroids and the smallest of the planets (if you use the planetological community’s definition). They formed early on as the other planets were gobbling up all of the rocks and dust that they could in order to become big and gravitationally strong. As a result, learning about these two baby planets can tell us a lot about how bigger planets form. Even better, it is possible that Ceres has a thick layer of water which may still be partially liquid; as a result, Ceres is one of the places in the Solar System that may harbor life as we know it.

Until recently, trhese were our best views of Vesta and Ceres (Image courtesy NASA)

Until recently, these were our best views of Vesta and Ceres
(Image courtesy NASA)

But the best thing about Ceres is what we don’t know about what we do know about it. For example, we know that Ceres has several spots that appear very bright when the spacecraft is in just the right place. But what we don’t know about those spots is why they are so bright. Is it due to a frozen lake of water ice at the bottom of a crater? Is it the plume of a cryovolcano? Is it the gleam of metal? Right now, we don’t have enough information to know for sure (my money is on the water ice). DAWN is going to change all of that.

 

This is our new, best image of Ceres (and they are only going to get better!) (Image courtesy NASA)

This is our new, best image of Ceres (and they are only going to get better!)
(Image courtesy NASA)

DAWN will take pictures of the entire surface of Ceres. And here’s the cool part – you will get to see those pictures just as soon as the scientists do. And here is the even cooler part – you can do science with those pictures yourself! The DAWN mission team and NASA have asked citizen scientists like you to look through the pictures as they arrive and identify any interesting landforms such as impact craters, volcanoes, and lava flows. You’ll even have the opportunity to name some of the features. If you’d like to take part (or just look through the amazing images), then fly over to:
 http://dawn.jpl.nasa.gov/DawnCommunity/asteroid_mappers.asp

March 5 – PING!

Today’s factismal: In the past week, snow has fallen in every state except Florida, Alabama, Georgia, and South Carolina.

Even though the Northern Hemisphere is twenty-six days into spring, some places are still getting lots of wintery weather. This past week saw a major winter storm sweep through the central part of North America, dumping a mixture of cold air, sleet, snow, rain, and chaos along its path. The storm (nicknamed “Thor” by some wags) has piled up as much as two feet of snow in Kentucky, and more than an inch of rain in Dallas. The high winds and precipitation have caused airplanes to skid off the runway and stranded motorists across the nation. But perhaps the people most frustrated by it are the meteorologists.

Every dot is a weather station that has recorded precipitation n the past week (Image courtesy NOAA)

Every dot is a weather station that has recorded precipitation n the past week
(Image courtesy NOAA)

The reason that meteorologists get frustrated by major storms like this is because the data we have is almost but not quite good enough to help them predict exactly when and when and how much precipitation there will be. And the reason for that is because the surface of the Earth is cluttered with things like trees and houses and the occaissional mountain that blocks the radar meteorologists use; as a result, radar can only track the precipitation until it gets close to the ground. To see what actually happens on the ground, the meteorologist needs to be there – or to have someone else be there.

A six hour PING report (Image from PING website)

A six hour PING report
(Image from PING website)

And that’s where you come in. NOAA’s National Severe Storms Laboratory has created an app called mPING (for “Precipitation Identification Near the Ground”); both Apple and Android versions are available. The way it works is simple: when you run into a bit of precipitation, you click the mPING icon, tell it what sort of precipitation you see, and go on your merry way. Your report is added to thousands of others and gets used to help improve our models of precipitation and to help predict where and when the next severe storm will head our way. To learn more, drift over to:
http://www.nssl.noaa.gov/projects/ping/

March 4 – The Tell-Tale Heart

Today’s factismal: A typical human heart moves about a third of a cup of blood through the body with each beat.

Ah, the human heart. Often derided as being frail and fragile, it is in fact one of our sturdiest organs. And no wonder, considering all of the trouble that we put it to. During a typical day, an adult’s heart will beat around 100,000 times. A kid’s heart works even harder; they will beat nearly 150,000 times each day! Add it up and over the course of a typical lifetime, a human heart will beat nearly 2.5 billion times.

Leonardo da Vicni's drawing of the human heart (Image courtesy Leonardo)

Leonardo da Vicni’s drawing of the human heart
(Image courtesy Leonardo)

The heart works so hard because it has to. The heart drives the circulatory system that delivers food and oxygen throughout the body and takes wastes and carbon dioxide away to be disposed of. The blood tissue will speed from your heart to your brain and back in just eight seconds; to reach your toes and get back takes just 16 seconds. Though you’ve got just about one and a half gallons of blood in your body, it is used over and over again. Each beat of an adult’s heart moves about a third cup of blood. Over the course of a day, your heart will pump nearly 2,000 gallons of blood throughout your body.

But anything that works that hard can sometimes have problems and the heart is no exception. Sometimes the valves in the heart wear out or just don’t close properly, allowing blood to leak through and reducing the flow; this is called valvular heart disease. Sometimes the heart loses its rhythm and beats irregularly; this is called an arrhythmia. Sometimes the heart doesn’t get enough blood to operate properly; this is called a myocardial infarction or “heart attack”.

Luckily, we know a lot about how to prevent these things from happening. If you get as little as thirty minutes of exercise (such as walking) each day, you’ll cut your chances of getting one of these problems by about 10%. Similarly, by eating a diet rich in fruits and vegetables and lean in alcohol and salt, you can reduce your chances of getting heart disease by nearly 20%.

Of course, there is more to having a healthy heart than just diet and exercise; genetics and other factors also play a part. And right now, a group of scientists are putting together a “big data” experiment to see just how much each of these things contributes to a healthy heart. At Health eHeart (get it?) they are asking for volunteers to take part in a study that will track participants for ten years. Every six months they’ll ask you to fill out a questionnaire on your health and will ask you to contribute information on your weight and activity level; some participants may also be given the opportunity to do cool things like wear a Holter monitor for a week or have a genetic sample taken. To join in on the fun, head over to:
https://www.health-eheartstudy.org/

March 3 – Moon Madness

Today’s factismal: 3753 Cruithne does not orbit the Earth.

Of late, there have been a lot of blog posts (even, sadly, on supposedly “science oriented” websites) claiming that Earth has a “second moon” named 3753 Cruithne (pronounced “CREW-eee-nuh”; it is the name of a Pictish king). As is often the case with things found on the internet, the truth is both less and more interesting. First, the less interesting part: 3753 Cruithne is not a moon of the Earth or any other planet; instead, it orbits the Sun all by itself. This may sound like nitpicking, but it is an essential part of the definition of the word “Moon”. Until 1655, everything that we saw in the sky was either a star, or a comet, or a planet with the sole exception of the Moon. Galileo’s discovery of four new things orbiting Jupiter was taken in stride; those things were planets according to the astronomers (even though Galileo called them stars). But in 1655, they started seeing planets orbiting Saturn as well. Before long, Saturn had five planets and a ring orbiting it while Jupiter’s planet count grew to ten. So the astronomers decided that they would redefine the word planet. If it was big enough to see and orbited the Sun, it was a planet. If it was big enough to see and orbited another planet, it was a moon. And so, because the asteroid 3753 Cruithne orbits the Sun and not the Earth, it isn’t a moon. (It isn’t a planet because it isn’t big enough; at just three miles across, it is too small to be round.)

So where did all of this nonsense about 3753 Cruithne being a second moon of the Earth get started? With the astronomers, of course. You see, astronomers love to think about what things look like, especially orbits. And they started looking at the orbits of Near Earth objects (i.e., things that had an orbit similar to Earth’s) and found several that had amusing (to the astronomers) orbits. If you flew abovethe Sun and watched 3753 Cruithne orbit, you would see it moving out toward Mars and back in toward Venus, crossing Earth’s orbit twice on each trip. And, thanks to the odd shape of 3753 Cruithne’s orbit, it actually takes about a year to complete each go-round. It would look something like this:

3753 Cruithne's orbit as seen from above the Sun (Image courtesy Jecowa)

3753 Cruithne’s orbit as seen from above the Sun
(Image courtesy Jecowa)

But if you stand on Earth and watch 3753 Cruithne orbit, it looks much different. Because Earth passes 3753 Cruithne in its orbit, it appears that the asteroid is making a “horseshoe” in space. So the astronomers giggled for a while about some asteroids being close enough for horseshoes and left it there. Which is where the internet found it. Unfortunately, most of the people on the internet aren’t astronomers. (You are shocked, I know.) As a result, they don’t know that the horseshoe “orbit” of 3753 Cruithne only happens when you look at the asteroid from the moving Earth; that it is a geocentric view. Since we know that the heliocentric view is much closer to reality, using a geocentric one to claim that an asteroid is the Earth’s second moon makes about as much sense as claiming that the Sun orbits the Earth. And 3753 Cruithne is hardly the only asteroid to look like it is orbiting Earth when it isn’t; just last year, 2014 OL339 was shown to also have a horseshoe orbit.

When viewed from Earth, it appears that 3753 Cruithne orbits us (as does everything else) (Image courtesy Jacowa)

When viewed from Earth, it appears that 3753 Cruithne (and everything else) orbits us
(Image courtesy Jecowa)

But that isn’t to say that the Earth doesn’t have a second moon every once in a while. (This is where life gets even more interesting than the internet thinks it is.) Due to the odd orbital interactions of all of the various bits of junk out there, every so often a small asteroid will get trapped in orbit around the Earth for a few days or a few weeks or a few years. When this happens, Earth truly does have a “second moon”; because these asteroids aren’t trapped by Earth’s gravity and are just “passing through”, they are referred to as coorbiting asteroids. In 1999, asteroid 2003 YN107 began a coorbit of Earth that lasted for seven years. And some experts estimate that we have a small, temporary “second moon” almost all the time!

The path of Earth's true "second moon" (Image courtesy NASA)

The path of Earth’s true “second moon”
(Image courtesy NASA)

So why aren’t we sure about how often the Earth has a “second moon” (even if it never is 3753 Cruithne)? Simply because asteroids are small and space is vast. As anyone who has ever tried to find a remote control in a room has discovered, it can take a long time to locate something if it is very small compared to the room that you are looking in. But having more people looking can help. And that’s where you can join in on the fun! The Asteroid Survey is looking for folks who are looking to be looking for asteroids! (Here’s looking at you, KD!) You’ll sort through photos, identifying objects as stars, asteroids, or “junk”. And you’ll be helping to identify the millions of bits of junk that fly through our Solar System and give us our second moons. To join in on the fun, orbit over to:
http://www.asteroidzoo.org/

March 2 – Glaring At The Kindle

Today’s factismal: A group of friendly adults cats is a clowder, a group of unfriendly adult cats is a glaring, and a group of kittens is a kindle.

If you were to take a guess, which do you think there are more of in the USA – pet dogs or pet cats? Believe it or not, there are slightly more pet cats (about 96 million) than there are pet dogs (about 83 million). Of course, the cat owners shouldn’t get too uppity; there are 145 million pet fish! Now guess which we have more of – stray dogs or feral cats? Believe it or not, we simply don’t know. The number of feral cats is estimated at between 70 million and 100 million; the number of stray dogs is about the same.

Watch out - she's a killer! (My camera)

Watch out – she’s a killer!
(My camera)

Part of the reason for this is because both dogs and cats can adapt easily to being feral. They are capable hunters and have plenty of places where they can shelter. And part of the reason for this is because both dogs and cats reproduce like rabbits; a single mother dog and her brood can add 67,000 puppies to the world in six years. Cat lovers, your best friend is even worse; a single mother cat can easily give birth to over 100 kittens in her lifetime and can have a family of more than 420,000! Currently, many groups are attempting to reduce this problem by instituting “Trap-Neuter-Return” programs that catch feral dogs and cats, neuter them, and them release them back into the wild. (Why not put them up for adoption? Sadly, most feral animals cannot be tamed after they reach adulthood – sort of like teenagers.)

This feral cat was adopted as a kitten and so was not returned after she was spayed (My camera)

This feral cat was adopted as a kitten and so was not returned after she was spayed
(My camera)

Needless to say, having that many new predators running around is not great news for their prey. Some experts estimate that feral cats kill almost four billion  birds and about 20 billion small mammals each year. Other experts think that the previous experts are bird brains and place the total toll much lower. The reason that there is such disagreement is because even though we’ve been living with cats for nearly 10,000 years now, we don’t really know much about how far they roam and what they do while they are out (again with the teenagers). But there is a citizen science project that is looking to change all that. The Cat Tracker project is asking volunteers to put a GPS on their cats before they let them outside and to share the data with the scientists. A select few participants will also be asked to mail in hair samples from their cat; an isotopic analysis of the hair will tell the scientists what (or who) the cats have been eating. To learn more about the project, slink over to:
http://cats.yourwildlife.org/